strategies for adding and subtracting within 0-20; such as adding just one more, a trick with nine
and eight, and subtracting using addition;

memorizing the basic addition and subtraction facts of single-digit numbers.

The PDF version of this book is enabled for annotation. This means that if you prefer, your student can fill it in on the computer, using the typewriter and drawing tools in Adobe Reader version 9 or greater.

In the first several lessons we study basic strategies for adding and subtracting within 0-20. After those,
we study the idea of completing and going over ten. For example, the child adds 8 + 5 by first adding
8 + 2 (which makes 10), and then adding the 3 that was "left over." These lessons prepare the student for
the next part of the book, which has to do with memorizing the basic addition facts.

The next lessons in the book, Adding with 9, Adding with 8, Adding with 7, and Adding with 6, provide
lots of practice for learning and memorizing the basic addition facts. There are 20 such facts:

Some children will accomplish this quicker, needing less practice. Some will need more practice. You can
also add in some Internet-based games (a list of online games is provided in the book).

After those lessons, we study subtraction. First, the child subtracts to ten. This means subtracting from 14,
15, 16, etc. so that the answer is 10, for example 16 − __ = 10. In the next step, we study subtractions with
an answer less than 10, such as 16 − 7. The student practices these by subtracting in two parts: First
subtracting to ten, then the rest. For example, 16 − 7 becomes 16 − 6 − 1, or 14 − 6 becomes 14 − 4 − 2.

The last part of the book includes various lessons titled Number Rainbows and Fact Families with ...,
which give lots of practice and reinforcement for the basic addition and subtraction facts. These lessons
also include many word problems. They emphasize the connection between addition and subtraction to
solve basic subtraction facts such as 13 − 8 or 15 − 6. Alongside them, you can also use games or
flashcards to reinforce the learning of the facts.

Learning and memorizing the basic addition and subtraction facts of single-digit numbers is very
important for later study. For example, regrouping (carrying/borrowing) in addition and in subtraction
requires that the student be able to recall all the sums of single-digit numbers and corresponding
subtraction facts efficiently and fluently. The goal is to memorize these facts, or at least become so fluent
with them that an outsider cannot tell if the student remembers the answer or uses some mental math
strategy to get the answer.

Strategies for addition and subtraction facts - two videos

Please see also the two videos below that explain several strategies for learning addition and
subtraction facts, many of which are studied in this book.

Customer Testimonials

We bought the light blue add/subtract and place value books from 2A forward to go back and get what my concept talented but math facts never mastered dd needs to review.

Keep doing the great work you're doing. It's amazing to see my dd age 12, who was doing fine with pre-algebra, knows all mult/division facts from homeschool years, but just never got the addition and subtraction facts (when she went to school) gain confidence with the reviews without any grade-level stigma.

Thanks!

Kate
February 2012

My son finally doesn't hate to do math. He is a little behind in math and this year with your workbooks he is well on his way back to grade level and with a great understading of how numbers work. Thanks Maria, for helping my son to learn and enjoy math!
Mabel
October 2010

I have a 2nd grade daughter who just "didn't get" math. We've been using another well known math program which was just moving too fast for her. Fortunately, I had purchased Mammoth Math [Add & Subtract] 2A over the summer and it has turned her into an "I get it" kid! We just completed 2A and will be starting 2B shortly. It's been an awesome supplement and my daughter looks forward to her daily math worksheets!
I can't believe how much more confident she's become in her computation skills and she's even soaring with the story problems.
Thanks Mammoth Math!
1 December 2008

The following is one of the winning entries to Math Mammoth 2008 Thanksgiving Contest.

Tomorrow we will finish the final two pages in your Blue Addition/Subtraction 2-A. My 10 yo daughter, Gracie, has Autism, and nearly
every math we have tried so far has been a impassable trial for her.
I really didn't know what to do anymore! Our family has been
homeschooling since 1993, and Gracie is our third child, but she has
difficulties that our other two simply did not have. I remembered
your website from previous web searches, and after reading about your
Light Blue series, a light bulb went on! Why not address her
individual math skill needs instead of trying to tackle a whole
curriculum again? With each of your books costing only a few dollars,
there was no risk at all! I ordered the Blue Addition/Subtraction 2-
A, downloaded, and printed that very day.

Well, it turned out to be just what Gracie needed! You teach math
topics efficiently and interestingly, with no extraneous fussiness.
After doing a few weeks of your math (slowly - 2 pages per day)
Gracie asked to know a bit more about the writer. We went online so
she could read your "about" page, and was so pleased to put a name
and face to your math books. You see, she discovered that you like
patterns, and believes you hide patterns all through your math
worksheets. In fact, she now notices lots of math patterns quickly,
and makes extra effort with her math worksheets to make sure Mrs.
Miller doesn't "trick" her. Her ability to see patterns makes
learning math facts so much easier. It never occurred to me (or my
Engineer husband) to explain math the way you do. You seem to be
speaking her "math language" and - finally - math makes sense to her.

Today, I'll be ordering the Blue A/S 2-B, so we can carry on with
Gracie's math seamlessly. I'm so thankful you wrote this particular
(Blue) series. I'm sure most homeschoolers order the Light Blue Full
Curriculum, and I hope it's a good fit for them. But, there are
students (perhaps with Special Needs, or just with Math Phobia) who
just can't manage a full curriculum. I hope they'll consider the Blue
series, which attacks math skills individually, in a way which builds
skill-upon-skill, and teaches little patterns and tricks in a very do-
able (and reasonably priced!) format.

Cheers,
Lauri Bolland (and Gracie)

Thank you so much for new edition of the Add/Subtract 2a book!! I gave the new pages as homework tonight and am amazed to see the excitement the rainbows have created working with inverse operations/fact families. Thank you, again! I love incorporating your worksheets into our lessons it has made my children confident independent workers! Your newsletters and blogs are so worth the read!! The information you have and receive about math is making a tremendous difference in my home everyday!! Your consideration, work, time, and effort is greatly appreciated by my family.

Shai Hawk

The followup to this book is Add & Subtract 2-B, which practices adding and subtracting two-digit numbers mentally and in columns (carrying and borrowing).

How and where to order

You can buy Math Mammoth books at:

Here at MathMammoth.com website — simply use the "Add to cart" buttons you see on the product pages.

CurrClick.com carries all Blue, Golden, and Light Blue series books as downloads. They accept credit cards and Paypal. You will be able to download the products immediately upon the purchase, and also return to your account at CurrClick to redownload.

Lulu offers printed copies for the Blue, Golden, and Light Blue series books.

By purchasing any of the books, permission IS granted for the teacher (or parent) to reproduce this material to be used with his/her students in a teaching situation; not for commercial resale. However, you are not permitted to share the material with another teacher.

In other words, you are permitted to make copies for the students/children you are teaching, but not for other teachers' usage.

Math Mammoth books are PDF files. You will need Adobe Reader to view them, including if you use a Mac or Linux. You can try other PDF viewers, but they seem to either omit or mess up some of the images.

Math Mammoth Tour

Confused about the different options? Take a 7-day virtual email tour around Math Mammoth! You'll receive:

An initial email to download your GIFT of over 400 free worksheets and sample pages from my books;6 other emails on 6 subsequent days that describe the different series of Math Mammoth products, answering the most commonly asked questions, including "What is the difference between all these different-colored series?"

This way, you'll have time to digest the information over one week, plus an opportunity to ask me personally which book would be right for your child or students.

Note: You will FIRST get an email that asks you to confirm your email address.
If you cannot find this confirmation email, please check your SPAM/JUNK folder.

"Mini" Math Teaching Course

This is a little "virtual" 2-week course, where you will receive emails on important topics on mathematics education. The topics include:

- Teaching multiplication tables
- Why fractions are so difficult
- How to help a student who is behind
- Should you use timed tests
- The value of mistakes
- And more!

You will also receive a GIFT of over 400 free worksheets and sample pages from my books right in the very beginning.

Note: You will FIRST get an email that asks you to confirm your email address.
If you cannot find this confirmation email, please check your SPAM/JUNK folder.

Math teaching tips & resources

Enter your email to receive math teaching tips, resources, Math Mammoth news & sales, humor, and more! I tend to send out these tips about once monthly, near the beginning of the month, but occasionally you may hear from me twice per month (and sometimes less often).